In a known mining or tunneling method a cutter head works the whole cross-section or face wall of a drift, tunnel, or heading. The rock is freed entirely by cutting which is an expensive method with high tool wear. Tunneling machines used for known methods are so called part-section machines where the cutter head, equipped with teeth, sweeps over the entire area of the face wall. Such tunneling machines have limited use if the mineral or rock to be mined is too hard or too abrasive. The tool wear exceeds any economically justified proportion, the harder the rock the lower the efficiency.
Machines not constructed for the purpose of tunneling are used whereby supporters carry heavy hydraulic hammers with a high knocking energy (see my U.S. Pat. No. 3,729,056 issued Apr. 24, 1973). These hammers are mostly attached to the arms of hydraulic excavators. Such equipment has also been used in coal mining. The hydraulic hammers of these machines first work at the soft coal in sight and then break down the solid rock after knocking off the loose material from the ceiling for safety reasons. The aforementioned hydraulic hammers are generally not suitable for working at the face wall, and therefore have no influence on solving the need for equipment suitable for driving drifts and similar enclosed below-ground hollow spaces.